Steam-boiler.



if. ERWOOD. STEAM BOILBR.

APPLIATION FILED APB. 29, 1907 PATENTED JULY 2L 1908.

No, 893,910. PATENTED JULY 21. 1908. J. ERWOGD.

STEAM BGILER.

APPLICATION FILED M129. 1907.

4 SHEETS-SEEN z.

i@ fa No. 893,910. MENTED JULY 21, 1908.

' J. BRWOOD.

STEAM BOILER.

APPMGATION Hman APR, 29. 1907.

4 sHmTSfsmI-T sK JOHN ERNOOI), OF CHICAGO, ILLINOIS.

STEAM-BOILER.

Specification of Letters Patent.

Patented July 21, 1998.

Application filed April 29, 1907. SerialNo. 370,892.

To all whom it 'may concern;

Be it known that I, JOHN ERwooD, a citizen of the United States, residing at Chicago, in the county of Cook, in the State of Illinois, have invented a new and useful Im rovement in Steam-Boilers, of. which the ollowing is a specification.

The object of my invention is to improve the Stirling boiler, orwater tube boilers wherein banks of tubes connect at either end to circular steam or water drums, and the invention consists in the features and combinations hereinafter described and claimed. Here-tofore in boilers of this class, where the drums are made of rolled sheets, which does not permit of anglesor flat surfaces, yowing to the impossibility of bracing them in the usual way, it has been necessary, with banks of tubes of more thanone row, to' employ'tubes of various curves or vbends, as in order to obtain the necessary support thetube must enter the circle'ofthe drum in a line with 1ts center. This curve .or bend however not only prevents the tubes `from being readily cleaned and examined by observation through them, but also prevents them frombecoming interchangeable with each other, and` in order to replace a damaged tube, one of special construction and shape must be secured. To obviate this difliculty and enable boilers of.tl1is class to be constructed with straightvtubesonly of standard shape, and to permit of interchangeability more or less, as the design of the boiler will allow, I use a s ecial form of tube sheet cast to the desire( shape, of a iiuid metal of desired physical qualities, such as cast steel of a high tensile and elastic strength, in which strengthening ribs of the metal are cast on the sheet and are a part of the permanent structure, without joint or rivet.

Inl the accompanying drawings, Figure 1 is a central vertical sectional view of a six drum boiler with my improvement, and Figs. 2 and 3 are views illustrating modifications, A, A1 and A2 are the lower or water drums and B, Bl and B2 are the upper or steam drums, C, C1 and C2' are the Athree banks of'heating tubes connecting the upper drums with the lower.-

D, D1 and D2 and E, E1 and E2, are my improved sheets, t, b1, b2 and b3 are steam and water circulation pipes connecting the upper drums together, while t, t5', be and 57 are connections composed of my improvement into which the straight tubes are expanded.. The connection b4 can comprise an independent casting as shown and running the entire length of the drum, or it can be a part of the principal sheet 'as shown at b5, b and t7, or it can even comprise the entire circumference of the drum, bs and b" also represent similar branch outlets and further illustrates the adaptability of this form of tube sheet as a means of avoiding the use of bent tubes.

Fig. 2 shows the banks of tubes C1V and C2 united to the one water drum Al, by means of 'a tubesheet with two angulated faces adjusted to accommodate two angles of .lower drum A through a single sheet D and covering a still greater circumference of the drum.

Fig. 4 is theplan of a drum fitted with my im rovement,` D while C represents the tube ho es, drum A being in this illustrationl mainly composed of rolled sheets with the tubesheet riveted thereto, the heads A are also com osed of the same material as the sheet an are flat and ribbedaiso on the inside, to be'described later.

Fig. 7, is a longitudinal' section of my tube sheetvto which is attached the flat cast head referred to above, and reinforced by ribs shown at el, the method of reinforcing my tube sheet is shown at d comprising ribs cast between the rows of tubes circumferentially vwith-the circle .of the drum while d4 are anrows of tubes and' compose sheet E3 and D3 and' while they are shown to be attached to drums A3 and B3 they canin themselves compose the entire circumference of the drum.

` Fig. 6 is still another modiiication, AL representing the outline'of the circle of a rolled drum D4 a sectional elevation of the tube. sheet, and conforming to the true circle of the drum asat C17; d", d1 and d are-the level ric surfaces or ste s in which the tubes are set, vthe open an irregular spaces at als 'are strengthened by-nieans of webs andin this instance, Jfurther reinforcing is by means of a rib cast on the outside between the tubes.

and circular with the drum7 said ribs to beinterposed either between each circumferential row, or the second or third row as may be desired, or the s acing of the tubes between their centers w permit.

Another constructive feature made possible with my improvement, and not possible with rolled sheets andffreferred to above, is shown in Figs. 8, 9 arid 10,'in Fig. 9 the tube is shown expanded into the sheet proper, as would be the case with a full length tu be in a new boiler, or where a newfull length tube was inserted, in this instance the annular ring is unemployed, the annular ring d4 yis cast onto the sheet D, tube holes of the required ysize are drilled into the sheets and faced'as at d6 into which'the tube is first expanded, the counter bore formed by the annular ring is also turned 0E or 'faced as at d5.

8 shows 'tube sheet D after the tube has been cut out and consequently shortened, as in dissembling, the shortened tube being rexpanded into the counter bore of the an-v nular ring at d4 into which is inserted a filling rin c, and both ring and tube expanded'toget er.

Fig. 10 is a modification, and can he employed wherein the thickness of the tube sheet D will permit of the required depth to present the turned surfaces of d5 and de.

Having thus described my invention, what l claim is 1. A drum for. steam boilersl adapted tobe directly: connected to groups of straight tubes, the longitudinal surface of the drum constructed with flat planes of cast metal and iitted with rows of holes for the reception of the tubes at right angles with their centers, the underside of the planes reinforced with ribs of metal cast thereon andrunning'between the rows of tubes and constituting a tube sheet entire, substantially as described.

2. A drum for steam boilers adapted to be directly connected to groups of tubes by means of cast tube sheets secured thereto, the longitudinal surface of the drum cast with dat planes or steps circumferential with the drum, and fitted with rows of holes for the reception of the tubes, reinforced with outer and inner circumferential ribs cast solidly thereon between the tubes, all constituting a tube sheet entire, substantially as described.

JOHN ERWOOD.

Witnesses:

F. W. ANDERSON, H. M. LANPHEAR. 

